Physics/Math References

Post any helpful references that you find in this thread, for the benefit of others. Also include a short description. I will try to categorize things by subject (i.e. particle physics, gravity, etc.). Leave a link, and a short explanation of what is at the link, and I will put it in its appropriate place in this thread.

Classical Mechanics/ElectrodynamicsOpen Text
This is a project by a former professor of mine (Walter Wilcox) to make free textbooks available to grad students. Included are textbooks on quantum mechanics, classical mechanics, and electrodynamics. These are good references, I think, although you have to watch out for typos. I have solutions to all of the problems in the electrodynamics book, if anyone is ambitious.

Particle PhysicsParticle Data Group
A complete listing of all known particles, and their measured properites. Also includes reviews on everything from statistics to grand unification.

Quantum Field Theory
Free pdf version of Mark Srednicki's QFT text book. I have used this book on occasion---it is easy to follow and is a good compliment to something like Peskin.

Weak Interactions in Particle Physics
Free textbook by Howard Georgi, about weak interactions. I've never studied from this book, but Georgi was one of the founders of the subject, so I feel confident that he knows what he is talking about.

WMAP. The marquee experiment for cosmology. WMAP measures temperature fluctuations when the photons first decouple from the plasma that is filling the early universe. This happens at t=380,000 years or so. WMAP has given us some truly remarkable information about the Big Bang and Inflation.

If we could find a free online book akin to Arfken's Mathematical Methods for Physicists, that would be incredibly useful. I wonder if such a thing exists... maybe MIT has a course like that with online notes?

Well I don't really need one for myself, I have access to a pretty big stash of resources. What I mean is if we could find a good public domain math methods book for people who want to learn physics, I think it would help alot. It could be used as a learning resource for people struggling to gain the background they need. Arfken's book, for instance, covers a massive array of difficult subjects such as Fourier transforms, boundary value problems, generating functions, etc. It's sprinkled with applications to problems in quantum physics, electromagnetism, nonlinear dynamics and many other areas of mathematical physics.

It would also be nice if an entry level math methods book were available to teach people here about complex numbers, geometry and other things they might be lacking. A kind of go-to reference guide when they need to learn a new concept.

Sometimes you encounter the odd good stuff online: this is a reference that covers quite a bit of ground, it looks at spiral forms in nature, in mathematics, in crystals; vortices and waves; and the anthropology (of numbers).
It's a google book with arbitrarily censored pages (about 2 or 3 every dozen or so) which means it's got missing bits, but what you can see looks quite good. It's an interesting treatment (I think) of the science of numbers, or mathematics and why we use it.